Microstrip patch antenna based UHF sensor for detection of Partial Discharge in High Voltage electrical equipments

High Voltage (HV) power apparatus are usually, the most critical and costly component in any power system. Sudden failure of such component leads to unwanted interruptions and catastrophic losses. Partial Discharges (PD) are reported as main reason for degradation of insulation system in any HV power apparatus. A successive occurrence of such discharges eventually leads to complete failure of the equipment. Therefore, it becomes important to monitor the PD in all HV power apparatus in order to detect incipient insulation problems, and to prevent further tragic failure. In the work, microstrip patch antenna has been designed in suitable manner for detection of Ultra High Frequency (UHF) signals, emitted due to occurrence of PD in HV power apparatus. An experimental study has been conducted in laboratory environment for testing of proposed sensors. Experimental results also correlated with the standard PD detection system (IEC60270). Result shows that, the proposed microstrip patch antenna can be effectively used as UHF sensor, and PD can be detected in the HV power apparatus in non-contact mode from a long distance. PD measurement with microstrip patch antenna is easy to install and also a cost effective solution for online condition monitoring of HV power apparatus.